Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

physiology test 3 > study guide gi physiology > Flashcards

study guide gi physiology Flashcards

1
Q

list the four basic layers of the gastrointestinal tract? from inside out?

A

muscosa
submucosa
muscularis
serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the innermost layer of the gi tract

A

mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are some of the functions of the mucosa

A

secretion of mucus and digestive enzymes and hormones
absorptions of nutrients
and protection against infectious disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the predominant tissue type that is found in the mucosa?

A

simple columnar epithelial cells which are found on a thin layer of connective tissue containing capillaries which nourish the cells and allow for absorption.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the two functions of the submucosa?

A

1) enables the gastrointestinal tract to regain its shape after food moves through it.
2) houses an intrinsic neuronal system called the enteric nervous system which regulates digestive activities such as motility, secretion, and blood flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the predominant tissue type found in the submucosa?

A

elastic fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the function of the muscularis?

A

sphincters (valves)
coordinated contractions of the muscularis layer are responsible for peristalsis and other contractions (segmentation) that propel food forward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the predominant cell types found in the muscularis?

A

circular and longitudinal layered smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the function of the serosa?

A

protective outermost layer of the GI tract, supports structures
secrete serous fluid that lubricates the organs reducing friction during movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the intestine also receives extrinsic innervation from the?

A

autonomic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what neurons regulate rest and digest?

A

parasympathetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

parasympathetic cholinergic neurons release what?

A

acetylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

acetylcholine does what?

A

increases secretions and contractions of the intestinal smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

the sympathetic neurons release what? which do what?

A

epinephrine and norepinephrine
drive the fight or flight response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the effect the sympathetic noradrenergic activity have on the gi system?

A

decreases the activity of intestinal smooth muscle, reduces secretions, and causes sphincters to contract, thus blocking the progression of intestinal contents.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how many nerve fibers from the enteric nervous system are there?

A

approximately 100 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

the majority of the ENS nerve fibers are found distributed where?

A

within the walls of the gastrointestinal tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

the enteric nervous system is primarily localized to two extensive plexuses which are?

A

myenteric plexus and the submucosal plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

a plexus is what?

A

a collection of nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the plexuses of the ENS are primarily found where?

A

the inner tissue layers of the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is the myenteric plexus located?

A

between the longitudinal and circular muscle layers of the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

the myenteric plexus is primarily responsible for?

A

control of muscular contraction and the mechanical aspect of digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

where is the submucosal plexus located?

A

in the submucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the function of the submuscosal plexus of the ENS?

A

responsible for controlling digestive secretions, absorption, and local contraction of the submucosal muscle leading to enfolding of the mucosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what do the efferent nerve fibers of the ENS do?

A

carry signals into the ENS from the ANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what does the afferent nerve fibers of the ENS do?

A

carry signal from the alimentary canal to the ENS triggering peristalsis and secretions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what allows for higher level control of digestion?

A

some afferent nerve fibers run into the vagus nerve and back to the brain stem allowing for higher level control of digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

where do afferent nerve fibers originate?

A

in wall of gut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

neurotransmitters control the gastrointestinal activity are both _______ and ________.

A

inhibitory and excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

List some examples of how neurotransmitters control GI activity

A

affect secretions into the lumen of the gut
control muscular contractions and gut motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

overactivity or under-activity of any neurotransmitter and ENS pathways can lead to?

A

excessive or diminished secretions
excessive or diminished absorptions
excessive motility
prolonged residents of food and chyme in various components of the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what sensation may you feel if the ENS is functioning abnormally?

A

pain and other sensations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

the esophagus recieves food mixed with? from where?

A

saliva
mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

relaxation of the __________- allows food to enter the upper portion of the esophagus.

A

upper esophageal sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what propels the food to the lower esophageal sphincter?

A

esophageal contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

the lower esophageal sphincter is ________ active. meaning what?

A

tonically active
it is in a contracted state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

the LES does what to allow food to enter the stomach?

A

relaxes reflexively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

the LES remains closed between what to prevent regurgitation of gastric contents into the esophagus?

A

swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

name the three different muscles found in the esophagus?

A

smooth muscle in the muscularis layer of the esophagus
skeletal muscle
smooth muscle fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

skeletal muscle in the esophagus is from the?

A

diaphragm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

smooth muscle fibers in the esophagus are from the?

A

stomach

42
Q

describe a burp?

A

occasionally the LES will open after a meal to expel swallowed air

43
Q

what is the temporary storage unit where chemical digestion of food begins?

A

stomach

44
Q

ingested contents and digestive secretions are mixed by coordinated muscular contractions forming a semi solid paste called?

A

chyme

45
Q

chyme is made of what two things?

A

ingested contents and digestive secretions

46
Q

the stomach is divided into three major regions called the?

A

cardia
fundus
antrum

47
Q

the lining of the stomach is covered with a _______ epithelial cells folded into gastric pits.

A

columnar

48
Q

each gastric pit is an opening of a duct into which one or more what empty?

A

gastric glands

49
Q

what is also known as the corpus of the stomach?

A

fundus

50
Q

the glands in the stomach house four type of secretory cells which are?

A

mucus cells

parietal cells

chief cells

endocrine cells

51
Q

what is the function of mucous cells?

A

mucus secreiton

52
Q

parietal cells primary cell function?

A

gastric acid secretion

53
Q

chief cells primary cell function?

A

pepsinogen and lipase secretion

54
Q

what is endocrine cells also called?

A

g cells

55
Q

what is endocrine cells primary cell function?

A

gastrin secretion

56
Q

where does most chemical digestion occur?

A

body and fundus of the stomach

57
Q

under normal conditions how much gastric juice is released from the gastric mucosa throughout the day?

A

3 liter

58
Q

gastric juice consists of?

A

electrolytes

hydrocholirc acid

mucus

intrinsic factor

59
Q

the primary secretion of the stomach is what produced by the parietal cells.

A

hydrogen ions

60
Q

what two mechanisms control gastric secretions?

A

neural and hormonal

61
Q

what three things stimulate parietal cells to secrete hydrogen ions?

A

acetylcholine

gastrin

histamine

62
Q

what can directly stimulate the proton potassium ATPase pump and parietal cells.

A

gastrin

63
Q

gastrin can stimulate what to secrete histamine?

A

Enterochromaffin ECL

64
Q

What inhibits acid secretion (2 things)

A

somatostatin and prostaglandins (specifically PGE 2)

65
Q

what type of cells produce gastrin?

A

g cells a type of endocrine cell that resides in the gastric glands of the gastric antrum

66
Q

chyme is passed from stomach to the duodenum by passing through the?

A

pyloric sphincter

67
Q

where is the primary site for mixing of chyme?

A

small intestine

68
Q

the small intestin is the primary site for mixing chyme with additional secretion from what two areas to promote digestion and reabsorption?

A

common bile duct and pancreatic duct

69
Q

the main method of the small intestine for increasing digestion and absorption is by?

A

providing large surface area to do so

70
Q

name 4 ways the small intestine has a large surface area?

A

length is 5 meters

mini folds of mucosa and submucosa allow for greater surface area

mucosal layer intestinal wall have finger like projection (villi) increasing absorption

epithelial cells have microvilli on the apical surface which helps to increase surface area

71
Q

the mucosa and submucosa’s villi and microvilli increase the absorptive surface area of the small intestine by how much?

A

600 fold

72
Q

how many layers of epithelial cells between the intestinal lumen and the systemic blood? and they shed how often?

A

1

every 2-6 days

73
Q

what two things will attach to receptors and causing influx of calcium in the regulation of gastric secretion?

A

acetylecholine and gastrin

74
Q

the colon consist of three parts which are?

A

duodenum

jejunum

ilium

75
Q

what is the primary function of the small intestines?

A

digestion/absorption of ingested nutrients (carbs, proteins, lipids)

76
Q

gastrin released by g cells stimulate ECL to release what?

A

histamine

77
Q

histamine binds to h2 receptors which increases what?

A

intracellular CAMP

78
Q

what acts in opposition to histamine to decrease intracellular cAMP

A

PGE2

79
Q

what act together to increase activity fo ATPase in the regulation of gastric secretion?

A

Calcium and cAMP

80
Q

the stomach is exposed to gastric juice with a pH of?

A

1.5 to 3.5

81
Q

the acidic environment aids in what? and destroys what?

A

aids in digestion and absorption of ingested contents

destroyes ingested bacteria and microorganisms

82
Q

the stomach is protected fromt he acidic environment by what?

A

by coating itself with mucosal barrier consisting of bicarbonate rich mucus

83
Q

the mucosal barrier strongly adheres to the epithelials cells of the stomach of the mucosa and protects it by maintain a thin layer of pH that is approximately?

A

6 to 7

84
Q

the stomachs underlying tissue between the epithelial cells and mucosa is protected from the acidic environment by what?

A

tight junctions preventing gastric juic from leaking into the underlying tissue

85
Q

smooth muscle cells in the walls of the GI tract are packed together in __________ and _________ bundles.

A

circular and longitudinal bundles

86
Q

what functionally couple the smooth muscle cells of the gi tract so contraction occurs synchronously.

A

gap junctions

87
Q

what is receptive relaxation?

A

as ingested food travels down the esophagus, the stomach reflexively relaxes to allow food to enter

88
Q

the stomach can accommodate about ____ liters of food?

A

1.5 liters

89
Q

what two things increase the frequency and magnitude of stomach contractions, augmenting gastric mixing.

A

gastrin and acetylcholine

90
Q

the gastric contents are mixed completely and converted to semi solid state called chyme usually within ___ hours after a meal is ingested.

A

4 hours

91
Q

in order for chyme to enter the small intestine the pyloric sphincter acts as a filter, allowing only _____ amount of chyme to pass through.

A

3 milliliters or less

92
Q

the rate of gastric emptying depens on what?

A

the chemical and physical contents of the stomach

93
Q

carbohydrate meals empty slow or fast?

A

fast

94
Q

fatty meals form a_______ at the top fo the chyme and move through the stomach _______.

A

oily layer

slowly

95
Q

dietary carbohydrates are most commonly composed of _______ and ______.

A

polysaccharides and disaccharides

96
Q

enterocytes can only absorb?

A

monosaccharides

97
Q

give an example of a polysaccharide?

A

starch

98
Q

give an example of a disaccharide

A

sucrose and lactose

99
Q

carbohydrate digestion occurs in _______ stages

A

two

100
Q

along the brush border of the intestinal lumen starch

A

physiology test 3 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions